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Lära Private Modifier | Encapsulation
Object-Oriented Programming in JavaScript
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Kursinnehåll

Object-Oriented Programming in JavaScript

Object-Oriented Programming in JavaScript

1. Classes & Objects
2. Encapsulation
3. Static
4. Inheritance

book
Private Modifier

Encapsulation is a process of control and validating the behavior of the class and class intances. Our Student has name and age attributes, and the user can access them from any place of program, and, of course, change it. Seems that it is not the best approach – you created a student with the name Mary, and suddenly you want to change it directly, or you want to change the age, and you assign it with some non-correct value, for example, -12.

That’s why there is an access modifier private: to forbid access to the attributes or method. You can access it only inside the class(for example, inside the method’s body). By default, all methods and attributes are public: you can access them anywhere in your program.

To make properties private, use #.

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class Student{ #name; #university; #age; #gpa; constructor(name, age){ this.#name = name; this.#age = age; console.log('Student created'); } sleep(){ console.log('I am sleeping right now!'); } happyBirthday(){ this.#age += 1; console.log('Today is my birthday'); } } student = new Student('Robert', 22);
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Uppgift

Swipe to start coding

Make age and name attributes public and let other attributes be private. Implement the constructor and then create a Student object and output the name of this object.

Lösning

Switch to desktopByt till skrivbordet för praktisk övningFortsätt där du är med ett av alternativen nedan
Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 2. Kapitel 1
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book
Private Modifier

Encapsulation is a process of control and validating the behavior of the class and class intances. Our Student has name and age attributes, and the user can access them from any place of program, and, of course, change it. Seems that it is not the best approach – you created a student with the name Mary, and suddenly you want to change it directly, or you want to change the age, and you assign it with some non-correct value, for example, -12.

That’s why there is an access modifier private: to forbid access to the attributes or method. You can access it only inside the class(for example, inside the method’s body). By default, all methods and attributes are public: you can access them anywhere in your program.

To make properties private, use #.

12345678910111213141516171819202122
class Student{ #name; #university; #age; #gpa; constructor(name, age){ this.#name = name; this.#age = age; console.log('Student created'); } sleep(){ console.log('I am sleeping right now!'); } happyBirthday(){ this.#age += 1; console.log('Today is my birthday'); } } student = new Student('Robert', 22);
copy
Uppgift

Swipe to start coding

Make age and name attributes public and let other attributes be private. Implement the constructor and then create a Student object and output the name of this object.

Lösning

Switch to desktopByt till skrivbordet för praktisk övningFortsätt där du är med ett av alternativen nedan
Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 2. Kapitel 1
Switch to desktopByt till skrivbordet för praktisk övningFortsätt där du är med ett av alternativen nedan
Vi beklagar att något gick fel. Vad hände?
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